Dermal compositions containing coenzyme q as the active ingredient

ABSTRACT

The present invention provides a composition for dermal application 
 
which comprises, as an active ingredient, an oxidized coenzyme Q represented by the formula (1):  
                 
 
in which n represents an integer of 1 to 12, and/or a reduced coenzyme Q represented by the formula (2):  
                 
in which n represents an integer of 1 to 12, the total content of the oxidized coenzyme Q and reduced coenzyme Q being 0.01 to 99% by weight relative to the whole amount of the composition. The present invention also provides a therapeutic composition for skin diseases, a cosmetic composition, a skin health care composition and a bath salt composition, each comprising the above composition for dermal application. The present invention is further provides a method for the treatment of skin diseases which comprises applying, to a patient suffering from a skin disease, the above-mentioned therapeutic composition for skin diseases, or a method for the treatment of skin diseases which comprises applying, to a patient suffering from a skin disease, the above therapeutic agent for skin diseases other than the oxidized coenzyme Q represented by the formula (1) and other than the reduced coenzyme Q represented by the formula (2) in parallel with a therapeutic composition for skin diseases.

TECHNICAL FIELD

The present invention relates to a composition for dermal applicationwhich contains a coenzyme Q as an active ingredient, in particular to acomposition for the treatment of skin diseases, a cosmetic composition,a skin health care composition and a bath salt composition, and to amethod for the treatment of skin diseases using that composition fordermal application.

BACKGROUND ART

Coenzymes Q are physiologically essential factors distributed widely inliving organisms, from bacteria to mammals, and occur as constituents ofthe mitochondrial electron transport system in cells of the livingorganism. Coenzymes Q function as carrier components in the electrontransport system by repeating oxidation and reduction in vivo, andreduced coenzymes Q are also known as antioxidants. In many animalsinclusive of human beings, or in fish and birds, coenzyme Q₁₀, which isa coenzyme Q whose side chain comprises 10 repetitions of a unit, ispredominant. Further, it is known that about 40 to 90% of this coenzymeQ₁₀ occurs in reduced form in living organisms.

As for the practical uses of coenzymes Q, oxidized coenzyme Q₁₀, forinstance, has been used as a drug for congestive heart failure and, inother fields than the pharmaceutical field, it has been used widely as anutrient or nutritional supplement, like vitamins. However, reducedcoenzyme Q₁₀ has not yet been put to practical use.

In Japanese Kohyo Publication Hei-09-501925, there is disclosed a dermalpreparation containing oxidized coenzyme Q₁₀ (ubiquinone) or reducedcoenzyme Q₁₀ (ubiquinol) as a coenzyme Q₁₀. In this document, however,it is disclosed only as one of a large number of examples of the activeingredient. As regards ubiquinol, in particular, no example is given forthe actual use thereof. It is described that such coenzymeQ₁₀-containing dermal preparations are effective against atopicdermatitis. However, the name of that disease, too, appears only as anexample of a large number of skin diseases. There is no relevantexample, hence the actual effect is unknown.

In Japanese Kokai Publication Hei-10-109933, the inventors of thepresent invention disclosed that the combined use of reduced coenzymeQ₁₀ and oxidized coenzyme Q₁₀ results in an improvement in oralabsorbability as compared with the single use of oxidized coenzyme Q₁₀.However, the effect of reduced coenzymes Q on absorbability uponadministration via other routes than the oral or its efficacy in atopicdermatitis was quite unknown.

It is a problem that skin diseases exert great influences on the life ofpatients not only physically but also mentally. In particular, thenumber of patients suffering from the intractable skin disease atopicdermatitis, among others, is tremendous and, further, the number ofadult patients with atopic dermatitis has been increasing in recentyears, causing serious problems in their leading a social life.

Steroids are generally known as therapeutic agents for atopicdermatitis. However, their use is restricted in not a few instancesbecause of their significant side effects and the possibility of theircausing the rebound phenomenon. Therefore, they are not sufficientlyeffective agents to bring about complete recovery from atopicdermatitis. Furthermore, in cases where steroids are ineffective, thereare, in fact, no therapeutic drugs available. It is also a socialproblem that there are victims of folk medicine.

Tacrolimus, which is an immunosuppressive, has recently been approved asa therapeutic agent for atopic dermatitis. However, its use in childrenhas not yet been approved because of a strong fear of its producing sideeffects; thus, it cannot be said to be a safe agent.

Under such circumstances, the advent of a therapeutic agent that can beused safely against atopic dermatitis is earnestly demanded.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a composition fordermal application which contains coenzyme Q, in particular coenzymeQ₁₀, as an active ingredient, and thus provide a safe and highlyeffective therapeutic agent for skin diseases, in particular atopicdermatitis.

As a result of investigations made by the present inventors to solve theproblems mentioned above, it was found that oxidized coenzyme Q₁₀ canproduce an excellent therapeutic effect on atopic dermatitis.Surprisingly, it was also found that when oxidized coenzyme Q₁₀ is usedin combination with an existing drug such as a steroid or tacrolimus, asynergistic effect, which is higher as compared with the single use ofsuch an existing drug, can be obtained.

Further, the inventors of the present invention prepared a dermalpreparation containing reduced coenzyme Q₁₀ and carried out apercutaneous absorption test, whereupon it was found that when acomposition containing a certain proportion of reduced coenzyme Q₁₀ ascoenzyme Q₁₀ is applied to the skin, a higher level of percutaneousabsorption can be attained as compared with a composition containingoxidized coenzyme Q₁₀ alone and the amount of coenzyme Q₁₀ in the skincan be much increased. Furthermore, it was surprisingly found that thecontent of reduced coenzyme Q₁₀, which is the active principle showingantioxidant activity, in skin can be markedly increased by applying acomposition containing reduced coenzyme Q₁₀ as compared with theapplication of oxidized coenzyme Q₁₀ alone. Heretofore, it has beenconsidered that oxidized coenzyme Q₁₀, when administered, is convertedto the reduced form in vivo and thus can show antioxidant activity.However, our studies revealed that the reduction of oxidized coenzymeQ₁₀ in skin proceeds only very slowly and, therefore, the reduced formlevel is far inferior to that attainable by application of a compositioncontaining reduced coenzyme Q₁₀. By increasing the content in skin ofreduced coenzyme Q₁₀, which shows strong antioxidant activity, itbecomes possible to expect higher levels of skin care activity ascompared with the application of oxidized coenzyme Q₁₀ alone.

Further, the inventor of the present invention evaluated an ointmentcontaining reduced coenzyme Q₁₀ for efficacy in the treatment of atopicdermatitis. As a result, it was found that a reduced coenzymeQ₁₀-containing ointment is by itself highly effective and comparable intherapeutic effect to prednisolone. It was also found that when areduced coenzyme Q₁₀-containing ointment is used in combination with asteroid or tacrolimus, a more powerful therapeutic effect can beproduced.

Furthermore, the inventor of the present invention found that suchdermal preparation containing coenzyme Q₁₀ as main active ingredient hasa skin restoration promoting activity. This suggests that coenzyme Q₁₀be effective also against skin diseases, typically decubitus.

Thus, the present invention provides a composition for dermalapplication which comprises, as an active ingredient, an oxidizedcoenzyme Q represented by the formula (1):

-   -   wherein n represents an integer of 1 to 12, and/or a reduced        coenzyme Q represented by the formula (2):    -   wherein n represents an integer of 1 to 12, the total content of        the oxidized coenzyme Q and reduced coenzyme Q being 0.01 to 99%        by weight relative to the whole amount of the composition.

The present invention also relates to a therapeutic composition for skindiseases, a cosmetic composition, a skin health care composition and abath salt composition, each comprising the above composition for dermalapplication.

The present invention is further concerned with a method for thetreatment of skin diseases

-   -   which comprises applying, to a patient suffering from a skin        disease, the above-mentioned therapeutic composition for skin        diseases, or    -   a method for the treatment of skin diseases    -   which comprises applying, to a patient suffering from a skin        disease, the a therapeutic agent for skin diseases other than        the oxidized coenzyme Q represented by the formula (1) and other        than the reduced coenzyme Q represented by the formula (2) in        parallel with above-mentioned therapeutic composition for skin        diseases.

In the following, the present invention is described in detail.

DETAILED DISCLOSURE OF THE INVENTION

The compounds represented by the above formula (1) are oxidizedcoenzymes Q, while the compounds represented by the above formula (2)are reduced coenzymes Q.

The method of obtaining oxidized coenzymes Q and reduced coenzymes Q isnot particularly restricted but the coenzymes Q can be obtained in theconventional manner, for example by synthesis, fermentation, orextraction from natural sources. Or, also employable is a methodcomprising, for example, subjecting the product obtained in the abovemanner to chromatography and concentrating the oxidized coenzyme Qfraction or reduced coenzyme Q fraction in an eluate. The oxidized formof coenzyme Q can be obtained by a method known in the art. The reducedfrom of coenzyme Q may be obtained by adding a conventional reducingagent, such as sodium borohydride or sodium dithionite (sodiumhydrosulfite), as necessary, to the above coenzyme Q and reducing theoxidized form of coenzyme Q contained in the above coenzyme Q to thereduced form of coenzyme Q in a conventional manner, followed byconcentration by chromatography. It is also possible to obtain thereduced form of coenzyme Q by treating an existing highly pure coenzymeQ with such as a reducing agent as mentioned above.

The method of obtaining the composition of the present invention is notparticularly restricted but the composition can be obtained, forexample, by dissolving the reduced form of coenzyme Q obtained in theabove manner and the oxidized form of coenzyme Q, which is commerciallyavailable or obtained by a method known in the art, either in admixtureor individually, in an appropriate base. Alternatively, the mixture ofreduced coenzyme Q and oxidized coenzyme Q as obtained in theabove-mentioned process for coenzyme Q production may be dissolved assuch in a base. The base may be selected according to need from amongthose conventionally used in pharmaceutical preparations, cosmetics andthe like within the limits within which the effects of the presentinvention will not be lessened.

In the composition of the present invention, the total proportion of theoxidized coenzyme Q and reduced coenzyme Q relative to the whole amountof the composition (proportion of the oxidized coenzyme Q relative tothe whole composition when the oxidized coenzyme Q alone is containedtherein, or proportion of the reduced coenzyme Q relative to the wholecomposition when the reduced coenzyme Q alone is contained therein) is0.01 to 99% by weight, preferably 0.1 to 95% by weight, more preferably0.5 to 50% by weight, still more preferably 1 to 30% by weight.

From the percutaneous absorbability viewpoint, the proportion of thereduced coenzyme Q relative to the total amount of the oxidized coenzymeQ and reduced coenzyme Q is preferably not less than 20% by weight, morepreferably not less than 40% by weight. However, a reduced coenzymeQ-free composition containing only the oxidized coenzyme Q can also bepreferably used. Further, the proportion of the reduced coenzyme Qrelative to the total amount of the oxidized coenzyme Q and reducedcoenzyme Q is preferably not more than 95% by weight.

The oxidized coenzyme Q and reduced coenzyme Q which can be used in thepractice of the present invention have a side chain in which, as shownby the above formulas (1) and (2), the number (n in each formula) ofrepetitions of the repeating unit is 1 to 12. Among them, those in whichthe number of repetitions of the repeating unit is 10, namely oxidizedcoenzyme Q₁₀ and reduced coenzyme Q₁₀, are particularly preferred.

The above composition for dermal application, therapeutic compositionfor skin diseases, cosmetic composition, skin health care compositionand bath salt composition may be intended for application to humans orfor application to pets, domestic animals and/or birds, in particulardogs and/or cats.

The dosage form of the dermal composition of the present invention isnot particularly restricted but includes, among others, cream-like,paste-like, jelly-like, gel-like, emulsion-like or liquid dosage formsprepared by dissolving or dispersing together the above agent(s) inappropriate bases (ointments, liniments, lotions, sprays, etc.), dosageforms prepared by spreading a solution or dispersion of the aboveagent(s) in a base onto supporting members (poultices etc.), and dosageforms prepared by spreading a solution or dispersion of the aboveagent(s) in a pressure sensitive adhesive composition onto supportingmembers (plasters, tapes, etc.).

The dermal composition of the present invention can be used as atherapeutic composition for skin diseases. The skin diseases which canbe treated with the composition include, but are not limited to, atopicdermatitis, decubitus, wounds, burns, psoriasis, eruptions, contactdermatitis, seborrheic dermatitis, lichen simplex chronicus Vidal,nummular eczema, housewives' eczema, solar dermatitis, prurituscutaneus, prurigo Devergie, drug eruption, lichen planus, pityriasisrubra pilaris, pityriasis rosea Gibert, erythema, erythrodermia, wounds,athlete's foot, and skin ulcer, among others.

In using the dermal composition of the present invention as atherapeutic composition for skin diseases, the composition may furthercontain a substance showing antioxidant activity, for example superoxidedismutase, catalase, glutathione peroxidase, vitamin E, vitamin C,glutathione, glutathione reductase, a polyvalent unsaturated fatty acidor the like. It may also contain a skin activating ingredient, forexample collagen, hyaluronic acid, mutin, a ceramide, squalene, squalaneor the like, or a percutaneous absorption promoter.

It may further contain a therapeutic ingredient for skin diseases otherthan the oxidized coenzyme Q and reduced coenzyme Q. As such ingredient,there may be mentioned those drugs which are generally used in the areaof dermatological treatment, for example anti-inflammatory agents,immunosuppressives, antibacterial substances, antifungal agents, anddisinfectants and, further, such antioxidant substances or skinactivating ingredients as mentioned above.

When the therapeutic composition for skin diseases according to theinvention is intended for use in the treatment of atopic dermatitis, itpreferably further contains a therapeutic agent for atopic dermatitisother than the oxidized coenzyme Q and reduced coenzyme Q. Suchtherapeutic agent for atopic dermatitis may be any of those generallyused in the treatment of atopic dermatitis, including steroids, morespecifically prednisolone valerate acetate, amcinonide, diflucortolonevalerate, dexamethasone valerate, clobetasol propionate, diflorasonediacetate, dexamethasone propionate, betamethasone dipropionate,difluprednate, fluocinonide, halcinonido, budesonide, hydrocortisonebutyrate propionate, betamethasone valerate, beclomethasonedipropionate, fluocinolone acetonide, triamcinolone acetonide,flumethasone pivalate, hydrocortisone butyrate, clobetasone butyrate,alclometasone dipropionate, dexamethasone, methylprednisolone acetate,prednisolone, and hydrocortisone acetate, and other drugs than steroids,for example tacrolimus, and antihistamines.

The dermal composition of the present invention can be used as acosmetic composition or a skin health care composition. Specific usesinclude, but are not limited to, cleansers, eye creams, eyeshadows,creams, milky lotions, skin lotions, perfumes, face powders,cosmeticoils, paste perfumes, powders, packs, shaving creams, shavinglotions, suntan oils, anti-suntan oils, suntan lotions, anti-suntanlotions, nail creams, nail enamels, bath cosmetics, rouge, mascara,lipsticks, lip creams, eyeliners, deodorants, cologne waters, etc.

In this case, the above composition may contain one or more of thosecosmetic auxiliaries so far used in the conventional cosmetic or skinhealth care compositions, for example preservatives, bactericides,perfumes, antifoaming agents, colorants, coloring pigments, thickeners,surfactants, emulsifiers, softening agents, moistening agents and/orhumectants, fats, oils, waxes and, further, alcohols, polyols, polymers,foam stabilizers, electrolytes, organic solvents, silicone derivatives,and other ingredients.

The dermal composition of the present invention can be used also as abath salt or like composition. The bath salt or like composition soreferred to herein means a composition to be dissolved in cold or warmwater for use thereof at the time of bathing. The bath salt or likecomposition of the present invention may comprise additive and otheringredients conventionally used in bath salt preparations.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a graphic representation of the relationship between theconcentration of coenzyme Q₁₀ in skin and the content of reducedcoenzyme Q₁₀ in sample. The vertical axis denotes the totalconcentration of coenzyme Q₁₀ in skin, and the horizontal axis denotesthe content of reduced coenzyme Q₁₀ in coenzyme Q₁₀ in the sampleapplied. Each bar represents the mean±standard deviation (n=4 or 5).

BEST MODES FOR CARRYING OUT THE INVENTION

The following examples and preparation examples illustrate the presentinvention in more detail. They are, however, by no means limitative ofthe scope of the present invention.

EXAMPLE 1

(1) Preparation of Test Sample 1

Reduced coenzyme Q₁₀ (0.1 g; containing about 5% of oxidized coenzymeQ₁₀) was melted on a water bath at 50° C. Thereto was added polyethyleneglycol 1500 (PEG 1500) melted in the same manner to make a total amountof 10 ml. This was made homogeneous by melting and mixing at 50° C. andthen allowed to solidify at room temperature to give an ointment-likecomposition.

(2) Preparation of Comparative Sample 1

Oxidized coenzyme Q₁₀ (0.1 g) was melted on a water bath at 50° C.Thereto was added PEG 1500 to make a total amount of 10 ml. This wasmade homogeneous by melting and mixing at 50° C. and then allowed tosolidify at room temperature to give an ointment-like composition.

(3) Percutaneous Absorption Test

The test sample 1 and comparative sample 1 were used as test substances.The test was carried out using male hairless rats (weighing 250 to 300g) fed under well-fed conditions. A 0.1-g portion of the test sample 1,comparative sample 1, or PEG 1500 as a control was applied to an area of3 cm square on the back of each hairless rat lightly anesthetized withether. Three hours, 8 hours or 24 hours after application, the rat wassacrificed by euthanasia, the applied area was washed thoroughly, and askin sample was taken. The skin sample was homogenized and extractedwith propanol, the extract was concentrated using a solid phase column,and the amount of coenzyme Q₁₀ in the skin was determined byhigh-performance liquid chromatography. The total amount of coenzyme Q₁₀in each skin sample is shown in Table 1. The numerical value shows themean value±standard deviation. TABLE 1 Coenzyme Q₁₀ concentration inskin (μg/g) 3 hr 8 hr 24 hr Control (PEG 1500)  1.51 ± 0.38  1.35 ± 0.39 1.62 ± 0.50 Oxidized coenzyme Q₁₀  8.32 ± 1.35  7.87 ± 1.75  7.63 ±2.69 (100)   (100)  (100)  Reduced coenzyme Q₁₀ ^(#1) 13.72 ± 0.70 17.96± 4.85 15.68 ± 3.95 (165***) (228*) (206*)Mean ± SD, n = 3 to 8.*p < 0.05, ***p < 0.001, in one-tailed Student's t-test.^(#1)Containing about 5% of oxidized coenzyme Q₁₀.

As shown above, it was revealed that the coenzyme Q₁₀ containing 95% ofreduced coenzyme Q₁₀ is very effective in increasing the amount ofcoenzyme Q₁₀ in skin as compared with 100% oxidized coenzyme Q₁₀.

Each of the skin samples mentioned above was homogenized and extractedwith hexane, the extract was evaporated to dryness and dissolved inethanol, and the proportion of reduced coenzyme Q₁₀ in skin wasdetermined by high-performance liquid chromatography with anelectrochemical detector. The amounts of reduced coenzyme Q₁₀ in skinthus found are shown in Table 2. Each numerical value means themean±standard deviation. TABLE 2 Reduced coenzyme Q₁₀ concentration inskin (μg/g) 3 hr 8 hr 24 hr Control (PEG 1500)  1.11 ± 0.26  0.84 ± 0.23 1.13 ± 0.39 Oxidized coenzyme Q₁₀  3.02 ± 1.22  4.99 ± 2.12  5.44 ±2.36 (100)   (100)  (100)  Reduced coenzyme Q₁₀ ^(#1) 12.55 ± 0.51 15.84± 4.56 12.99 ± 4.81 (414***) (317**) (239*)Mean ± SD, n = 3 to 8.*p < 0.05, **p < 0.01, ***p < 0.001, in one-tailed Student's t-test.^(#1)Containing about 5% of oxidized coenzyme Q₁₀.

As shown above, it was revealed that the coenzyme Q₁₀ containing 95% ofreduced coenzyme Q₁₀ is very effective in increasing the amount ofreduced coenzyme Q₁₀ in skin as compared with 100% oxidized coenzymeQ₁₀. Although the amount of reduced coenzyme Q₁₀ in skin is graduallyincreased by the reduction of oxidized coenzyme Q₁₀ in the treated skin,the rate thereof is not very rapid. Even after 24 hours afterapplication of oxidized coenzyme Q₁₀, the amount of reduced coenzyme Q₁₀in skin is only half or less as compared with the level 3 hours afterapplication of reduced coenzyme Q₁₀.

EXAMPLE 2

(1) Preparation of Test Sample 2

The sample was prepared in the same manner as described above in Example1 for test sample 1 except that a mixture of oxidized coenzyme Q₁₀ andreduced coenzyme Q₁₀ in a mixing ratio of 80:20 by weight was used.

(2) Preparation of Test Sample 3

The sample was prepared in the same manner as described above in Example1 for test sample 1 except that a mixture of oxidized coenzyme Q₁₀ andreduced coenzyme Q₁₀ in a mixing ratio of 60:40 by weight was used.

(3) Preparation of Test Sample 4

The sample was prepared in the same manner as described above in Example1 for test sample 1 except that a mixture of oxidized coenzyme Q₁₀ andreduced coenzyme Q₁₀ in a mixing ratio of 40:60 by weight was used.

(4) Preparation of Test Sample 5

The sample was prepared in the same manner as described above in Example1 for test sample 1 except that a mixture of oxidized coenzyme Q₁₀ andreduced coenzyme Q₁₀ in a mixing ratio of 20:80 by weight was used.

(5) Percutaneous Absorption Test

The test was carried out in the same manner as in Example 1 using thetest samples 2, 3, 4 and 5 as well as the comparative sample 1 as testsamples.

The results of the test are shown in FIG. 1. In FIG. 1, the verticalaxis denotes the total amount of coenzyme Q₁₀ and the amount of reducedcoenzyme Q₁₀ in skin at 3 hours after application, and the horizontalaxis denotes the content (% by weight) of reduced coenzyme Q₁₀ relativeto the total amount of coenzyme Q₁₀ in the sample applied. Each barindicates the mean value.

As is evident from FIG. 1, the composition in which the proportion ofreduced coenzyme Q₁₀ was 20% by weight gave a significantly increasedconcentration of reduced coenzyme Q₁₀ in skin as compared with thecomposition comprising oxidized coenzyme Q₁₀ alone. Further, with thecomposition containing reduced coenzyme Q₁₀ in a proportion of 40% byweight, a still higher concentration was observed as compared with thecomposition containing reduced coenzyme Q₁₀ in a proportion of 20% byweight. From these results, it was revealed that when it contains notless than 20% by weight of reduced coenzyme Q₁₀, the composition of thepresent invention can undoubtedly increase the amount of reducedcoenzyme Q₁₀ in skin as compared with the composition containingoxidized coenzyme Q₁₀ alone or the composition containing less than 20%by weight of reduced coenzyme Q₁₀ relative to the total amount ofcoenzyme Q₁₀.

EXAMPLE 3

Therapeutic Effect in Atopic Dermatitis Model Mice (NC Mice) -1

The method of Hirasawa et al. (Oyo Yakuri (Applied Pharmacology), Vol.59, No. 6, pp. 123-134, 2000) was used for the evaluation. Ointmentscontaining oxidized coenzyme Q₁₀ and ointments containing reducedcoenzyme Q₁₀ (containing 5% of oxidized coenzyme Q₁₀ in coenzyme Q₁₀)were evaluated for therapeutic effect in atopic dermatitis model mice(NC mice) Dermatitis was induced in each group of 7 NC mice bysensitizing (once a week) using a hapten. On the occasion of the thirdsensitization, the treatment with each test compound was started. Thecoenzyme Q₁₀-containing ointment (1%) was applied at a dose of 0.1 gevery day, while the positive control prednisolone ointment was appliedonce every other day. In the group in which the prednisolone ointmentand the coenzyme Q₁₀ ointment were used combinedly, the ointments wereapplied alternately. The therapeutic effect was evaluated on a scoringscale of 0 to 3 (0: no symptom, 1: slight, 2: medium, 3: severe) for the5 items: 1-pruritus, 2-rubefaction, bleeding, 3-edema, 4-abrasion,tissue deficit, 5-crusting, dryness. The differences between thedermatitis scores at the start of the test and those on day 15 after thestart of application are shown in Table 3. Each data indicates themean±standard deviation. TABLE 3 Test group Increase in dermatitis scoreControl group 4.4 ± 1.18 (100) 1% Oxidized coenzyme Q₁₀ ointment 3.3 ±2.14 (75) 1% Reduced coenzyme Q₁₀ ointment* 3.1 ± 2.04 (70) Prednisoloneointment (P) 2.1 ± 1.35 (48) Prednisolone ointment (P) 2.1 ± 1.35 (100)P + 1% oxidized coenzyme Q₁₀ ointment 1.1 ± 1.07 (52) P + 1% reducedcoenzyme Q₁₀ ointment* −1.3 ± 1.98 (—)Mean ± SD, n = 7*Total coenzyme Q₁₀ contained about 5% of oxidized coenzyme Q₁₀.

A greater score value indicates a higher level of aggravation ofdermatitis during testing. In the oxidized, and reduced coenzyme Q₁₀ointment groups, the ointments showed an obvious aggravation preventingeffect, like in the positive control prednisolone ointment, as comparedwith the control group. In the group of combined use with prednisolone,a more powerful therapeutic effect was shown as compared with the groupof single use of prednisolone, and the reduced coenzyme Q₁₀ ointment, inparticular, gave a score lower than the score at the start of testing,indicating its dermatitis healing ability. It has so far been quiteunknown in the art that ointments containing a coenzyme Q as its mainactive ingredient is actually effective against atopic dermatitis in themanner mentioned above. Furthermore, it has never been anticipated thatwhen used combinedly with a steroid, a coenzyme Q can show such a morepotent effect.

EXAMPLE 4

Therapeutic Effect in Atopic Dermatitis Model Mice (NC Mice) -2

The effect of the single use of a high concentration coenzyme Q₁₀ointment (10%) and the effect of the combined use of Protopic ointment(tacrolimus preparation), a therapeutic agent for atopic dermatitis, anda low concentration coenzyme Q₁₀ ointment (1%) were examined by carryingout the same test as in Example 3. In the single use evaluation group,the test ointment was applied every day and, in the combined useevaluation group, Protopic ointment was applied at a does of 0.1 g oncea week and 0.1 g of the low concentration coenzyme Q₁₀ ointment on theremaining 6 days per week. In a control group, Protopic ointment wasapplied singly 6 times a week. In a positive control group, aprednisolone ointment was applied every other day. The results obtainedon the 15th day after commencement of application are shown in Table 4.Each value indicates the mean±standard deviation. TABLE 4 Test groupIncrease in dermatitis score Control group 4.1 ± 0.90 (100) 10% Oxidizedcoenzyme Q₁₀ ointment 4.0 ± 1.53 (98) 10% Reduced coenzyme Q₁₀ ointment*2.9 ± 1.21 (71) Prednisolone ointment (P) 2.7 ± 2.14 (66) Protopicointment (P) 5.4 ± 1.90 (100) P + 1% oxidized coenzyme Q₁₀ ointment 3.7± 1.80 (69) P + 1% reduced coenzyme Q₁₀ ointment* 3.0 ± 1.73 (56)Mean ± SD, n = 7*Total coenzyme Q₁₀ contained about 5% of oxidized coenzyme Q₁₀.

The high-concentration reduced coenzyme Q₁₀ ointment was roughlycomparable in therapeutic effect to the positive control prednisoloneointment, indicating that it can show a potent therapeutic effect evenwhen used singly. On the other hand, Protopic ointment in the single usegroup showed no efficacy probably due to the small number ofapplications. However, when Protopic ointment was used in combinationwith the low concentration coenzyme Q₁₀ ointment, a distinct synergisticeffect was shown and aggravation was suppressed. That the coenzyme Q₁₀ointments used combinedly with tacrolimus also showed a synergisticeffect like in the combined use with the steroid preparation indicatesthat the synergistic effect of the coenzyme Q₁₀ ointment on atopicdermatitis is not specific to the steroid preparation.

EXAMPLE 5

Incised Wound Healing Test in Rats

SD rats (male, 12-week-old) were clipped of hairs and divided intogroups of 10 animals to make the mean body weights of the groups roughlythe same, and subjected to the test. Each animal was given an incisionwound along the median line under diethyl ether anesthesia. The incisionwound was stapled at three sites using Michel's clips, and a 1% oxidizedcoenzyme Q₁₀ ointment or a 1% reduced coenzyme Q₁₀ ointment was appliedat a dose of 0.2 g/day for 4 days. Two control groups, namely anontreated group and an ointment base group treated with the same doseof the ointment base, were used. Three days after incision, the Michel'sclips were removed and, four days after incision, each animal waseuthanized by overanesthesia with diethyl ether, the skin around theincision was peeled off, and skin sections were prepared. The skinsections were measured for tension on a tensile tester.

As a result, it was noted that oxidized coenzyme Q₁₀ and reducedcoenzyme Q₁₀ have a skin repair promoting effect.

EXAMPLE 6

Oxidation Stability Evaluation of Reduced Coenzyme Q₁₀ in Ointment

Reduced coenzyme Q₁₀-containing ointments were evaluated for oxidationstability. The ointment bases used were PEG 1500, a hydrophilicointment, an absorptive ointment, and a simple ointment. The PEG 1500used was a product of Wako Pure Chemical Industries, and the hydrophilicointment, absorptive ointment and simple ointment used were respectivelythe products according to the Japanese Pharmacopoeia. Using therespective bases and reduced coenzyme Q₁₀, ointments were prepared inthe same manner as in Example 1. The thus-prepared reduced coenzyme Q₁₀ointments were stored at 23° C. for 2 weeks either in air or in a vesselpurged with nitrogen, and the proportion of the reduced form of coenzymeQ₁₀ in each ointment was determined by HPLC. The results thus obtainedare shown in Table 5. TABLE 5 Proportion of reduced coenzyme Q₁₀ (%)*²Concentration 4° C. 23° C. 23° C. Base (%)*¹ in air in air in nitrogenPEG1500 1 87.5 56.4 62.3 PEG1500 10 92.5 94.4 93.6 Hydrophilic ointment1 — 75.1 79.3 Absorptive ointment 1 — 29.8 5.3 Simple ointment 1 — 83.983.6 Mean, n = 2*¹Concentration of coenzyme Q₁₀ in ointment*²Proportion of reduced coenzyme Q₁₀ in total coenzyme Q₁₀ in ointmentafter 2 weeks of storage under respective conditions.—Not tested.

In the reduced coenzyme Q₁₀ ointments prepared by using simple ointmentand hydrophilic ointment, respectively, as bases, about 80% of coenzymeQ₁₀ retained the reduced form after the 2 weeks of storage whereas, inthe PEG 1500-based and absorptive ointment-based ointments, only 60% and30%, respectively, of the reduced form remained. As regards theoxidation stability of reduced coenzyme Q₁₀ in the ointments, thesubstitution of the storage vessel atmosphere with nitrogen showed noprotective effect. When the PEG 1500-based ointment was stored at 4° C.in a refrigerator, the enzyme stability was assured for 2 weeks.Evaluation of the dependency on the concentration of reduced coenzymeQ₁₀ in ointment revealed that the 10% ointment is higher in stabilitythan the 1% preparation, namely the higher the concentration is, themore stable the preparation is.

PREPARATION EXAMPLE 1

A coenzyme Q₁₀-containing hydrophilic ointment was prepared by aconventional method according to the following formulation. Hydrophilicointment 99.000% by weight coenzyme Q₁₀  1.000% by weight

PREPARATION EXAMPLE 2

A coenzyme Q₁₀-containing W/O cream was prepared by a conventionalmethod according to the following formulation. Glycerol sorbitan fattyacid ester  6.000% by weight Microcrystalline wax  1.000% by weightOlive oil  3.000% by weight Liquid paraffin  19.000% by weight Magnesiumstearate  1.000% by weight Propylene glycol  3.700% by weight Magnesiumsulfate (MgSO₄.7H₂O)  0.700% by weight Coenzyme Q₁₀  1.000% by weightDehydrated salt to make 100.000% by weight

PREPARATION EXAMPLE 3

A coenzyme Q₁₀-containing W/O emulsion was prepared by a conventionalmethod according to the following formulation. Polyoxyethylene glycerolsorbitan fatty acid ester  3.600% by weight Polyoxyethylene fatty acidester  1.400% by weight Cetearyl alcohol  2.000% by weight Mineral oil,GP 9  20.000% by weight Paraben mixture q.v. Magnesium sulfate(MgSO₄.7H₂O)  0.700% by weight Coenzyme Q₁₀  1.000% by weight Calciumchloride (CaCl₂)   0.85% by weight Dehydrated salt to make 100.000% byweight

PREPARATION EXAMPLE 4

A coenzyme Q₁₀-containing W/O lotion was prepared by a conventionalmethod according to the following formulation. Glycerol sorbitan fattyacid ester  1.300% by weight Polyoxyethylene fatty acid ester  3.700% byweight Neutral oil  6.000% by weight Liquid paraffin, GP 9  14.000% byweight Propylene glycol  3.800% by weight Magnesium sulfate (MgSO₄.7H₂O) 0.700% by weight Ribonic acid  1.500% by weight Coenzyme Q₁₀  1.000% byweight Desalted water to make 100.000% by weight

INDUSTRIAL APPLICABILITY

The composition of the present invention, which has the aboveconstitution, is excellent in percutaneous absorption of coenzyme Q₁₀and highly effective in the treatment of skin diseases, such as atopicdermatitis, and in skin health care.

1. A composition for dermal application which comprises, as an activeingredient, an oxidized coenzyme Q represented by the formula (1):

in which n represents an integer of 1 to 12, and/or a reduced coenzyme Qrepresented by the formula (2):

in which n represents an integer of 1 to 12, the total content of theoxidized coenzyme Q and reduced coenzyme Q being 0.01 to 99% by weightrelative to the whole amount of the composition.
 2. The composition fordermal application according to claim 1, wherein the proportion of thereduced coenzyme Q relative to the total amount of the oxidized coenzymeQ represented by the formula (1) and the reduced coenzyme Q representedby the formula (2) is not less than 20% by weight.
 3. The compositionfor dermal application according to claim 2, wherein the proportion ofthe reduced coenzyme Q relative to the total amount of the oxidizedcoenzyme Q represented by the formula (1) and the reduced coenzyme Qrepresented by the formula (2) is not less than 40% by weight.
 4. Thecomposition for dermal application according to any of claims 1 to 3,wherein the proportion of the reduced coenzyme Q relative to the totalamount of the oxidized coenzyme Q represented by the formula (1) and thereduced coenzyme Q represented by the formula (2) is not more than 95%by weight.
 5. The composition for dermal application according to claim1, which does not contain any of the reduced coenzymes Q represented bythe formula (2) but contains an oxidized coenzyme Q represented by theformula (1).
 6. The composition for dermal application according to anyof claims 1 to 5, wherein the oxidized coenzyme Q represented by thegeneral formula (1) is oxidized coenzyme Q₁₀ and the reduced coenzyme Qrepresented by the general formula (2) is reduced coenzyme Q₁₀.
 7. Thecomposition for dermal application according to any of claims 1 to 6,which is to be applied to a human.
 8. The composition for dermalapplication according to any of claims 1 to 6, which is to be applied topets, a domestic animal and/or a bird.
 9. The composition for dermalapplication according to claim 8, which is to be applied to a dog and/ora cat.
 10. A therapeutic composition for skin diseases which comprisesthe composition for dermal application according to any of claims 1 to9.
 11. The therapeutic composition for skin diseases according to claim10, which is to be used for the treatment of at least one skin diseaseselected from the group consisting of atopic dermatitis, decubitus,wounds, burns, psoriasis, eruptions, contact dermatitis, seborrheicdermatitis, lichen simplex chronicus Vidal, nummular eczema, housewives'eczema, solar dermatitis, pruritus cutaneus, prurigo, drug eruption,lichen planus, pityriasis rubra pilaris Devergie, pityriasis roseaGibert, erythema, erythrodermia, wounds, athlete's foot, and skin ulcer.12. The therapeutic composition for skin diseases according to claim 10or 11, which further comprises a therapeutic ingredient for skindiseases other than the oxidized coenzyme Q represented by the formula(1) and other than the reduced coenzyme Q represented by the formula(2).
 13. The therapeutic composition for skin diseases according toclaim 12, wherein the therapeutic ingredient for skin diseases otherthan the oxidized coenzyme Q represented by the formula (1) and otherthan the reduced coenzyme Q represented by the formula (2) is atherapeutic agent for atopic dermatitis other than the oxidized coenzymeQ represented by the formula (1) and other than the reduced coenzyme Qrepresented by the formula (2).
 14. The therapeutic composition for skindiseases according to claim 13, wherein the therapeutic agent for atopicdermatitis other than the oxidized coenzyme Q represented by the formula(1) and other than the reduced coenzyme Q represented by the formula (2)is a steroid or tacrolimus.
 15. A cosmetic composition which comprisesthe composition for dermal application according to any of claims 1 to9.
 16. A skin health care composition which comprises the compositionfor dermal application according to any of claims 1 to
 9. 17. A bathsalt composition which comprises the composition for dermal applicationaccording to any of claims 1 to
 9. 18. A method for the treatment ofskin diseases which comprises applying, to a patient suffering from askin disease, the therapeutic composition for skin diseases according toany of claims 10 to
 14. 19. A method for the treatment of skin diseaseswhich comprises applying, to a patient suffering from a skin disease, atherapeutic agent for skin diseases other than the oxidized coenzyme Qrepresented by the formula (1) and other than the reduced coenzyme Qrepresented by the formula (2) in parallel with a therapeuticcomposition for skin diseases according to any of claims 10 to 14.